Vehicle Open Roof Drive Cable Segmentation

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Solution Overview

Problem

Existing open roof systems for vehicles face challenges in efficiently managing long drive cables, leading to increased costs, necessary room requirements, and cable resistance, as well as issues with cable slack and differing movement requirements between movable elements.

Innovation Solution

The introduction of an elongated second part connected to the drive cable assembly at its second end allows for the movement of a second movable element in the opposite direction to the first, while maintaining the elongated part in the same lateral guide, with options for continuous or temporary connection, and varying properties such as stiffness, to optimize cable length and movement efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If long drive cables are used to operate both movable elements from a single motor, then one motor can drive both elements, but cable resistance and cable slack increase

Engineering Contradiction:
Improvemotor quantityVSAvoidcable performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The drive cable assembly is segmented into a flexible first part connected to the motor and a second part that may be flexible or substantially stiff. This segmentation allows the cable system to be divided into functional sections, with the second part being shorter and stiffer to reduce resistance and slack while the first part maintains flexibility for motor operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the drive cable assembly have different properties - the first part is flexible to accommodate motor movement, while the second part is substantially stiff (made of plastic or metal alloy) to minimize cable resistance and slack. This local differentiation of cable properties optimizes performance in different zones of the system.

Inventive Principle:
Principle #3Local quality

2Reliability

If the drive cable is made substantially stiff to reduce cable slack and resistance, then cable performance improves, but the cable cannot accommodate motor movement and positioning

Engineering Contradiction:
Improvecable performanceVSAvoidcable flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The drive cable assembly is divided into a flexible first part that connects to the motor and allows motor movement, and a second part that is substantially stiff to reduce slack and resistance. This segmentation enables each part to have the appropriate flexibility for its specific function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cable system employs local quality by making different sections have different mechanical properties - the first part near the motor remains flexible to accommodate motor positioning, while the second part extending to the movable element is substantially stiff to minimize deformation and slack under load.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If the first and second movable elements require different amounts of cable movement, then each element can be optimized for its function, but a single motor cannot drive both elements effectively

Engineering Contradiction:
Improveelement movement independenceVSAvoiddrive system coordination
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connecting part is made movable relative to the first part of the drive cable assembly, allowing dynamic adjustment of the connection point. This enables the system to accommodate different cable movement requirements for the first and second movable elements while still being driven by a single motor, as the connecting part can shift position to optimize cable utilization.

Inventive Principle:
Principle #15Dynamics

4Device complexity

If the second part of the drive cable assembly is made long to reach the second movable element, then both elements can be operated, but costs and room requirements increase

Engineering Contradiction:
Improvecable routing simplicityVSAvoidcable length
Core Design Contradiction:
Device complexityVSLength of stationary object

Solution Approach 1:

The second part of the drive cable assembly is made substantially stiff and relatively short compared to what would be required if a single flexible cable spanned the entire distance. This localized stiffening allows the cable to maintain its shape and transfer force efficiently over a shorter effective length, reducing both physical cable length and associated costs.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2674312B1Openable roof system for a vehicle
Publication Date: 2017.05.03 INALFA ROOF SYST GROUP
  • EP2674312B1 patent drawingFigure 1
  • EP2674312B1 patent drawingFigure 2
  • EP2674312B1 patent drawingFigure 3

AI summary

An open roof system for a vehicle comprises at least first and second movable elements (4,5;24;41,42;51,52), which are each movable between a position in which it is retracted, and a position in which it is deployed. At least two drive cable assemblies (7,8) transfer the torque of a motor (6) to said movable elements (4,5;24;41,42;51,52). The stationary part (3) comprises at least first and second guiding channels (9,9',10,10';17,17') and laterally positioned guides (11,11') for respectively guiding the drive cable assemblies (7,8) and the movable elements (4,5;24;41,42;51,52). The drive cable assemblies (7,8) comprise a flexible first part (13,14) having first and second ends (13',14';13",14"), the first part (13,14) being driven by the motor (6). The first end (13',14') of the flexible first part (13,14) is connected to the first movable element (4,24,41,42), in a first direction, and the second end (13",14") is guided in a first guiding channel (9,9',10,10') in the lateral guide (11,11'). The second end (13",14") is oriented in a direction substantially parallel to the first end (13',14') towards said first movable element (4,24,41,42). The drive cable assembly (7,8) further comprises an elongated second part (15,16), guided in a second guiding channel (17,17') in a second direction towards said second movable element (5,51,52) and connected thereto. The second guiding channel (17,17') is oriented substantially parallel to the first guiding channel (9,9',10,10') in the lateral guide (11,11'). During at least part of the operation, the elongated second part (15,16) moves substantially in the same direction as the second end (13",14") of the first part (13,14) of the cable assembly (7,8).